Transcription
Hydrogeology and Water Quality of theWest Valley Creek Basin, Chester County,PennsylvaniaBy Lisa A Senior, Ronald A. Sloto, and Andrew G. ReifU.S. GEOLOGICAL SURVEYWater-Resources Investigations Report 94-4137Prepared in cooperation with theCHESTER COUNTY WATER RESOURCES AUTHORITYLemoyne, Pennsylvania1997
U.S. DEPARTMENT OF THE INTERIORBRUCE BABBITT, SecretaryU.S. GEOLOGICAL SURVEYGordon P. Eaton, DirectorFor additional informationwrite to:Copies of this report can bepurchased from:District ChiefU. S. Geological Survey840 Market StreetLemoyne, Pennsylvania 17043-1586U.S. Geological SurveyBranch of Information ServicesBox 25286Denver, Colorado 80225-0286
CONTENTSPageAbstract. 1Introduction .3Purpose and scope . 3Description of the study area . 4Well-numbering system. 7Previous investigations. 7Acknowledgments. 8Hydrogeology.8Geology . 8Carbonate rocks. 10Vintage Dolomite . 10Kinzers Formation . 10Ledger Dolomite. 10Elbrook Formation . 12Conestoga Limestone. 12Noncarbonate rocks. 12Leucocratic and intermediate felsic gneiss . 12Chickies Quartzite . 12Antietem Quartzite and Harpers Phyllite. 12Octoraro Phyllite. 13Wissahickon Formation. 13Peters Creek Schist. 13Hydrology. 13Ground water. 13Water-bearing zones. 15Aquifer and well characteristics. 16Hydraulic conductivity. 16Specific yield. 18Specific capacity and well yield. 18Water levels . 20Depth to water . 20Fluctuations. 20Regional flow. 26Surface water . 30Ground-water/surface-water relations . 33Water budget . 40Water use . 40Basin budget . 42Recharge. 45Water quality.46Ground water . 49
CONTENTS ContinuedPageWater quality ContinuedPhysical properties and field-determined constituents. 49Major ions and constituents. 51Metals and other trace constituents . 58Radionuclides. 60Organic compounds . 62Volatile organic compounds . 62Semivolatile organic compounds. 63Pesticides . 64Other organic compounds. 64Surface water. 65Base flow. 65Physical properties and field-determined constituents . 68Major ions and constituents . 75Metals and other trace constituents. 86Streambed sediment. 90Benthic invertebrate indices. 91Relation between ground-water and surface-water quality . 93Summary.98References cited .100ILLUSTRATIONSPLATES[In Pocket]Plate 1. Geology and location of selected wells and springs, West Valley Creek Basin,Chester County, PennsylvaniaFIGURESFigures1-3. Maps showing:1. Location of the West Valley Creek Basin, Chester County, Pennsylvania . .42. Physiographic provinces, southeastern Pennsylvania.53. Generalized geology of the West Valley Creek Basin, Pennsylvania,and location of streamflow-measurement stations .64. Structural cross-sections of Chester Valley, Pennsylvania . 115. Water-bearing openings in noncarbonate and carbonate fractured-rock aquifers . 146. Geophysical logs for well CH-4147 completed in carbonate rock, West Valley CreekBasin, Pennsylvania. 177. Map showing location of observation wells and precipitation gages, West ValleyCreek Basin, Pennsylvania .21IV
ILLUSTRATIONS-ContinuedPageFigures8-10. Graphs showing:8. Water-level fluctuations in observation wells completed in carbonateand noncarbonate rocks, West Valley Creek Basin, Pennsylvania,January 1990 - January 1992 .229. Relation between precipitation and the water levels measured in wellCH-249, West Valley Creek Basin, Pennsylvania, 1990-91.2310. Precipitation and water levels in well CH-3916, West Valley Creek Basin,Pennsylvania, 1990-91 .2411. Hydrograph of well CH-2738 and daily precipitation, March 10-April 6,1992,West Valley Creek Basin, Pennsylvania .2512-13. Maps showing:12. Generalized regional ground-water flow directions, West ValleyCreek Basin, Pennsylvania .2713. Altitude and configuration of the water-table determined from waterlevels measured May-June 1984, and in the fall of 1983,1987,1990,and 1992, West Valley Creek Basin, Pennsylvania .2814-17. Graphs showing:14. Daily mean discharge at streamflow-measurement stations 01480887,[Westl Valley Creek at Ravine Road near Downingtown, and01480870, East Branch Brandywine Creek below Downingtown,Pennsylvania, 1990-91 .3115. Instantaneous discharge at 15-minute intervals at streamflowmeasurement stations 01480887, [Westl Valley Creek atRavine Road near Downingtown, and 01480870, East BranchBrandywine Creek below Downingtown, Pennsylvania,October and December, 1990 .3216. Base flow and streamflow, at streamflow-measurement station 01480887,[Westl Valley Creek at Ravine Road near Downingtown,Pennsylvania, 1990-91 .3317. Base flow at streamflow-measurement station 01480887, [Westl ValleyCreek at Ravine Road near Downingtown and ground-water levelsin a well (CH-249) completed in carbonate rocks, West ValleyCreek Basin, Pennsylvania, 1990-91.3518. Map showing location of discharge-measurement sites (October 1990 and 1991)and reconnaissance water-quality-measurement sites (August 1990),West Valley Creek Basin, Pennsylvania .3719-21. Graphs showing:19. Base flow and exported sewer flow for the West Valley Creek Basin,Pennsylvania, 1990-91 .4520. Relation between concentrations of sodium and chloride in groundwater in the West Valley Creek Basin, Pennsylvania .5421. Distribution of concentrations of nitrite plus nitrate as nitrogen inground water in the West Valley Creek Basin, Pennsylvania,grouped by lithology: 1) gneiss and quartzite; 2) carbonate rock;3) phyllite and schist .56
ILLUSTRATIONS ContinuedPageFigures22. Piper diagrams showing relative major ion concentrations for ground water fromwells open to carbonate and noncarbonate rocks in the West Valley CreekBasin, Pennsylvania.5723. Map showing location of stream-sampling sites in the West Valley Creek Basin,Pennsylvania.6624-32. Graphs showing:24. Distribution of discharge measured at 15 stream-sampling sites at timeof sample collection, West Valley Creek Basin, Pennsylvania,August 1990 - July 1991.6825. Distribution of monthly stream temperature, pH, alkalinity, specificconductance, and dissolved oxygen concentrations at 15 samplingsites on West Valley Creek, Pennsylvania, August 1990 - July 1991. 7026. Seasonal variations in monthly base flow, dissolved oxygenconcentrations, temperature, alkalinity, specific conductance,and pH at stream-sampling site WVC-3, West Valley Creek Basin,Pennsylvania, August 1990 - July 1991.7227. Relation between dissolved oxygen concentration and temperaturein monthly base-flow samples at 15 sites on West Valley Creek,Pennsylvania, August 1990 - July 1991.7328. Concentrations of dissolved oxygen in monthly base-flow samplesat 15 sites on West Valley Creek, Pennsylvania, August 1990 July 1991.7329. Relation between alkalinity and discharge in monthly base-flowsamples at 8 sites on West Valley Creek, Pennsylvania, August1990-July 1991 .7430. Distribution of selected dissolved major ion concentrations in monthlybase-flow samples at 15 sites on West Valley Creek, Pennsylvania,August 1990-July 1991.7631. Concentrations of chloride in base-flow samples collected in autumn,1971-93, at biological monitoring site 01480903 [West] Valley Creekat Mullsteins Meadow (WVC-15), Pennsylvania, and seasonalKendall trend slope estimator. 7932. Seasonal variations in chloride concentrations in monthly base-flowsamples from selected mainstem and tributary stream sites, WestValley Creek Basin, Pennsylvania .8033. Piper diagram showing relative concentrations of major ions in stream samplescollected September 5-6,1990, West Valley Creek Basin, Pennsylvania .8234-38. Graphs showing:34. Distribution of dissolved nutrients and turbidity concentrations inmonthly base-flow samples from 15 sites on West Valley Creek,Pennsylvania, August 1990 - July 1991.8335. Distribution of dissolved iron, manganese, lithium, and boronconcentrations in base-flow samples from 15 sites on West ValleyCreek, Pennsylvania, August 1990 - July 1991.87VI
ILLUSTRATIONS ContinuedPageFigures 34-38. Graphs showing Continued:36. Reported and measured lithium loads at stream site WVC-2, West ValleyCreek Basin, Pennsylvania, August 1990 - July 1991.8937. Brillouin's benthic invertebrate diversity indices at biological monitoringsite 01480903 [West] Valley Creek at Mullsteins Meadow (WVC-15),Pennsylvania, showing improvement in diversity index values,1973-92 .9238. Lithium and chloride loads at selected stream sites on West Valley Creek,Pennsylvania, September 5-6,1990 .95TABLESTable1. Stratigraphic section of geologic units in the West Valley Creek Basin, Pennsylvania .92. Number of water-bearing zones reported per 100 feet of uncased boreholedrilled in carbonate and noncarbonate rocks, West Valley Creek Basin,Pennsylvania .163. Minimum, maximum, and median reported specific capacity for wells in the WestValley Creek Basin, Pennsylvania. 184. Minimum, maximum, and median reported well yield and depth for domesticand nondomestic wells in the West Valley Creek Basin, Pennsylvania . 195. Minimum, maximum, and median reported depth to water in wells in the WestValley Creek Basin, Pennsylvania.206. Monthly and annual streamflow and base flow at streamflow-measurementstation 01480887, [West] Valley Creek at Ravine Road near Downingtown,Pennsylvania, 1990-91.347. Discharge measurements in the West Valley Creek Basin, Pennsylvania,October 22 and 27,1990 .388. Discharge measurements in the West Valley Creek Basin, Pennsylvania, October 9,10, and 11,1991.399. Stream temperature and specific conductance at selected reconnaissance stream sites,West Valley Creek Basin, Pennsylvania, August 1-8,1990 .4010. Major water withdrawals in the West Valley Creek Basin, Pennsylvania, 1991.4111. Annual precipitation in the West Valley Creek Basin, Pennsylvania, 1990-91 .4312. Basin water budget for West Valley Creek above streamflow-measurementstation 01480887 at Ravine Road near Downingtown, Pennsylvania, 1990-91.4413. Estimated recharge to West Valley Creek Basin, Pennsylvania, 1990-91.4614. Mean annual concentrations and loads of selected major constituents in precipitationat Valley Forge, Pennsylvania, 1982-91 .4715. Primary and secondary maximum contaminant levels established by the U.S.Environmental Protection Agency for selected inorganic and organicconstituents in drinking water.4816. Summary of ground-water physical properties and field-determined constituents forwater samples from wells in the West Valley Creek Basin, Pennsylvania .50vii
TABLES ContinuedPageTable17. Summary of major ion concentrations in ground water, West Valley Creek Basin,Pennsylvania .5218. Summary of nutrient concentrations in ground water, West Valley Creek Basin,Pennsylvania .5519. Summary of concentrations of selected dissolved metals and trace constituents inground water, West Valley Creek Basin, Pennsylvania.5920. Summary of radioactivitity and uranium concentrations in ground water, West ValleyCreek Basin, Pennsylvania .6121. Summary of volatile organic compounds detected in ground water, West Valley CreekBasin, Pennsylvania.6322. Drainage area, stream sources, and land use for sampling sites in the West ValleyCreek Basin, Pennsylvania.6723. Lithium isotopic ratios and lithium concentrations in surface water and ground water,West Valley Creek Basin, Pennsylvania.9624. Record of selected wells and springs, West Valley Creek Basin, Pennsylvania . 10525. Physical and chemical properties, and results of chemical analyses for major ions,nutrients, iron and manganese in ground water, West Valley CreekBasin, Pennsylvania.11026. Results of chemical analyses for selected metals and trace constituents in groundwater, West Valley Creek Basin, Pennsylvania. 11627. Results of radiochemical analyses for radon-222, radium-226, radium-228, uranium,and gross-alpha- and beta-particles in ground water, West Valley Creek Basin,Pennsylvania .11828. Results of chemical analyses for volatile organic compounds in ground water,West Valley Creek Basin, Pennsylvania. 11929. Results of chemical analyses for semivolatile organic compounds in ground water,West Valley Creek Basin, Pennsylvania. 12330. Results of chemical analyses for organochlorine insecticides in ground water,West Valley Creek Basin, Pennsylvania. 12431. Results of chemical analyses for organophosphorous insectides in ground water,West Valley Creek Basin, Pennsylvania. 12532. Results of chemical analyses for triazine herbicides in ground water, West ValleyCreek Basin, Pennsylvania. 12633. Results of chemical analyses for gross polychlorinated biphenyls and napthalenes inground water, West Valley Creek Basin, Pennsylvania. 12734. Discharge, physical and chemical properties, and results of chemical analyses fornutrients, major ions, and selected trace constituents in surface water,West Valley Creek Basin, Pennsylvania, August 1990 - July 1991,and October 1991.12835. Results of chemical analyses for selected metals and trace constituents in surfacewater, West Valley Creek Basin, Pennsylvania, November 1990. 160VIII
CONVERSION FACTORS AND ABBREVIATIONSBy.MultiplyTo obtainLengthinch (in.)foot (ft)mile square mile (mi )gallon (gal)2.5903.7850.003785square kilometerlitercubic meterFlowcubic foot per second (ft3/s)gallon per minute (gal/min)million gallons (Mgal)million gallons per dayper square mile [(Mgal/d)/mi2]0.028320.0000633,7850.0169cubic meter per secondcubic meter per secondcubic metercubic meters per second per squarekilometerSpecific capacitygallon per minute per foot[(gal/min)/ft]cubic meter per second per meter0.000207Hydraulic conductivityfoot per day (ft/d)meter per day0.3048Transmissivityfoot squared per day (ftVd)meter squared per day0.0929Temperaturedegree Fahrenheit ( F)5/9 ( F-32) Cdegree Celsius ( C)Other Abbreviationsmilligrams per liter (mg/L)milliliter (ml)parts per million (ppm)picocuries per liter (pCi/L)gram (g)kilogram (kg)micrograms per kilogrammicrograms per liter (ug/L)Sea level: In this report, "sea level" refers to the National Geodetic Vertical Datum of 1929 a geodeticdatum derived from a general adjustment of the first-order level nets of the United States and Canada,formerly called Sea Level Datum of 1929.IX
Hydrogeology and Water Qualityof
27. Results of radiochemical analyses for radon-222, radium-226, radium-228, uranium, and gross-alpha- and beta-particles in ground water, West Valley Creek Basin, Pennsylvania .118 28. Results of chemical
